1. Field
Inter-cell interference cancellation is a topic of interest for a variety of communication systems. For example, a local area radio system can complement existing cellular wide area systems (GSM/UMTS/HSPA/LTE). Unlike a wide area cellular system, a local area system can utilize time division duplex (TDD) bands to take advantage of the additional available bandwidth. Inter-cell interference reduction, such as provided by certain embodiments of the present invention, may benefit such systems. Inter-cell interference reduction can also be very useful for wide area systems with overlapping coverage area or in a co-channel deployment of wide area and local area networks, often referred to as heterogeneous networks.
2. Description of the Related Art
Inter-cell interference cancellation can be performed a variety of ways. In certain cases, cells with heavy mutual interference coordinate their resource usage. Thus, cells can be aware of the resources used by the other cell and can take that into account when scheduling their users.
Inter-cell interference cancellation can exhibit an inter-cell interference coordination mechanism. Some resources restrictions on power levels of single stream and multistream transmission are used. These approaches can assume that a radio system has an architecture that includes a radio network controller (RNC).
Other approaches call for cells with heavy mutual interference to coordinate their resource usage. The cells, therefore, must be aware of the resources used by the other cell and can take those resources into account when scheduling their users. In some cases, the cells negotiate the resources to be used. Other schemes involve coordinating inter-cell interference by defining resources with lower transmit power that will create less interference to neighboring cells.
Distributed signaling mechanisms for establishing a frequency reuse pattern can be based on local agreements between nodes, which become more complex as the number of variables in the negotiation increase.